Multiple choice

The results of analysis of a raw water sample are given below:

 
Turbidity 5 mg/l
pH 7.4
Fluorides 2.5 mg/l
Total Hardness 300 mg/l
Iron 3.0 mg/l
MPN 50 per 100 ml

From the data given above, it can be inferred that water needs removal of

  1. turbidity followed by disinfection

  2. fluorides and hardness

  3. iron, followed by disinfection

  4. both (2) and (3)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 Fluoride should be less than 1.5 mg/L, hardness between 75 - 115 mg/L as $CaCO_3$ iron 0.3 mg/L and MPN 1 per 100 mL (presence of pathogenic bacteria). Hence, water needs removal of fluoride, hardness iron and followed by disinfection to reduce MPN to 1 per 100 mL.

Keep practicing — related questions